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By A Brodbeck, AT Spathis

Australian regulatory control of ground vibration and airblast arising from mining, quarrying and civil construction operations is spread across a number of federal, state and local authorities and across a number of departments with various jurisdictions. The Australian Standard AS 2187.2 contains an informative appendix on damage-related criteria and it is the primary reference for the regulators. The complete standard and the informative appendix is currently undergoing major revision with a focus for the latter on implementing frequency-dependent criteria for ground vibration. Certain directions for change have been raised for consideration by the standing committee, ranging from fundamental issues of measurement and interpretation and others that overlap human comfort criteria. It is anticipated that some of the suggestions will eventually make their way into future standards after an adequate period of consultation and consideration by both the Australian public and others involved in the associated industries.

Jan 1, 2005

By Greg Parker

"As the Explosives Industry continues to evolve and condense, those involved, such as Blasters,Contractors, Distributors and Consultants, continue to be challenged by both internal and externalforces. Increased pressure by government agencies, higher safety standards, new levels of technology and mandatory certification programs, are forcing us to expand our awareness and increase our levels of efficiency. These higher standards require increased awareness. Increased awareness requires better training programs and better supervision with emphasis on production and the employee. This means the desire to improve must be instilled from the top down. this paper will explore the current impediments to this goal and discuss the possible solutions for achieving greater safety awareness, increased production and higher levels of personal achievement. Through the use of audio/visual aids, I will attempt to show the discrepancies as well as the solutions."

Jan 1, 1999

By Duan Baofu, Wang Xuguang, Song Jinquan

In this paper, the model of optimizing selection on preparation of Powdery Emulsion Explosives(PEE) is established by the Neural Net Theory(NNT). On the basis of some data in the study of PEE, the training, prediction and optimizing selection of the Neural Net (NN) model are finished by a compiling procedure. The results indicate that the model is helpful to the preparation of PEE and worthy to extend and apply broadly. KTYWORDS Neural Net Powdery Emulsion Explosives Preparation Optimizing Selection

Jan 1, 2003

By Lyall Workman

"Many new technologies, useful to the mining and quarrying have recently come to market. Some are applicable to drilling and blasting operations. Others apply to subsequent mining unit operations and can generate data for objective assessment of blasting results. These new technologies can accurately capture the information component of blasthole drilling, andindeed of each unit operation. Knowledge can be extracted from this information and passed forward and back through the mining system to improve operations and factually assess results. This leads to an evolving and improving system."

Jan 1, 2001

By Larry R. Fletcher

A misfire results when explosives fail to detonate as planned during a mine blast. Accidental detonation of misfires is a frequent cause of personal injury, equipment damage, and lost production. In an effort to minimize these problems, the Bureau of Mines investigated the causes of misfires, methods for detecting misfires, and procedures for their disposal. During this investigation, input was obtained from explosives suppliers, mining companies, blasting contractors, blasting consultants, and governmental agencies. Additional data were obtained through detailed analysis of blasting accidents involving misfires.

Jan 1, 1983

By Jerry Wallace

A highway bridge demolition project to allow shipping access to a new container port in Puget Sound ran into trouble when contract-stipulated mechanical means of demolition failed. Blasting was then employed under less than ideal conditions and was successful.

Jan 1, 1999

By Dale Ramsey

Emulsion explosives have become the product of choice for many blasting applications and are not limited to just extreme wet hole conditions or special application environments as in the past. Today’s novel emulsion technology has evolved over many decades, allowing a great diversity of formulations, Emulsion explosives can be effectively designed to produce very high energies, cap sensitive high explosive cartridges to bulk blasting agents, with varying viscosities, stable VOD’s, excellent water resistance, long shelf life and sleep time. They are also conducive to the mixture of emulsion, An/F0 blends in varying proportions and are amenable to any type of sensitizer. The key to a stable, reliable and consistent emulsion formulation is the careful mixing of the internal phase, which consists of a solution of oxidizer salts suspended as microscopically fine droplets, with the surrounding continuous fuel phase. There are few blasting applications today where some form of an emulsion explosive cannot fit the application. In massive, hard rock, dense, tightly jointed and fine grained rock types, the emulsion explosives are the best choices in creating new fracture networks for good fragmentation with a few alternatives. In such environments, emulsions with expanded drill patterns often result in better economics than the use of straight AnLFo. This paper will cover emulsion formulations, sensitizing options, product testing, material handling, and blast optimization, Emulsion explosives characteristics have also proven to reduce adverse environmental effects such as noxious fumes, ground vibration, and airblast while still remaining cost effective.

Jan 1, 2000

By Jerry Wallace

Construction of a new grammar school required blasting within three meters of the existing school. Due to changes not anticipated at time of bid opening, blasting had to take place while approximately 200 children were in attendance inside the building. Blasting with children in such close proximity forced the blaster to review and revise a systematic approach to construction blasting and make changes to previous Rules of Thumb guidelines. The revised rules of thumb place Blaster-in-Charge at the top of the List. Other changes specific to the project included putting in place a blasting safety plan that included communicating the serious job hazards to teachers and students. The plan included stringent lockdown guidelines establishing school procedures for accounting for each student prior to the countdown-to-blast being implemented. Emergency communications channels were kept open so that any scheduled blast could be aborted at the last instance.

Jan 1, 2001

By Jeff Hammer, John McGregor

"The Twin Tunnels, originally constructed in 1964, have become a major choking point for trafficheading up to and returning from the Colorado high country along the I-70 corridor. To increase traffic flow, the Colorado Department of Transportation undertook the first widening of the East Bound Tunnel in 2013. After the successful completion of that project, CDOT began the widening of the West Bound Tunnel in 2014. Both projects had a limited schedule for tunnel construction of just nine months. The innovative blasting and demolition of the existing tunnel lining was a crucial component to the success of both projects. During the construction of the West Bound project in 2014 a large amount of surface bench blasting using conventional methods ran concurrently to the West Bound tunnel excavation to allow for enough room for the new tunnel portals."

Jan 1, 2016

By P Geddes, K Grohs, C K. McKenzie, M Morrish

Low grade surface gold mining at the Acacia Resources, Union Reefs Gold Mine in Australia's Northern Territory, involves the excavation of benches in three slices after blasting. Blast patterns span zones of high and low grade ore, as well as zones of waste, and selective excavation is required in order to maintain economical head grades for the carbon-in-leach processing plant.

Jan 1, 1998

By Paul Sterk

In underground mining a great deal of time, money, effort, and resources have been used in the effort to minimize blast-induced damage. This damage occurs to the back, ribs, and pillars when the energy of the explosive is released back into the rock due to over confinement or the overloading of explosives in the perimeter holes. This damage can result in roof falls, dilution of ore, excessive rock bolting, scaling, screening, shot-creteing and other safety and support issues.

Jan 1, 2003

By L. Trivino

Blast-induced damage criterion based on the peak particle velocity has worked reasonably well for estimating building damage. However, the same criterion cannot be used to estimate damage to rock and mine structures such as shaft and tunnel walls. It does not take into account the nature of seismic radiation pattern in the near-field, which is very different than what is obtained at far-off distances. To investigate this phenomenon, a systematic study has been carried out involving single-hole blasts and normal production blasts, with explosive source ranging from nearly point source charges to standard borehole sizes (6-7 m long explosive column), with charge weight varying from 0.5 kg to 30 kg. In the near-field, it is shown that, both P-wave and S-wave take a dominant position compared to the mainly surface waves measured in the far-field. These are shown to depend strongly not only on the length of the explosive column but also the way it is initiated in the borehole (i.e. direct vs. reverse initiation in the borehole) with respect to the target location. The seismic radiation patterns were recorded by high-frequency triaxial accelerometer stations grouted in the rock mass. This study describes the nature of seismic radiation in the near-field from long and short charges, the role of initiation direction and their effect on frequency with respect to sensor locations or target area of interest, and their implication in prediction of blast-induced damage in the near field.

Jan 1, 2009

By Catherine T. Aimone-Martin, Meyers Joseph A.

A new strain-based criteria is being adopted for rock blasting in New York City (NYC). This criteria is based on several years of research involving vibration measurements of tall structures during blasting within several feet from buildings designated historic and Landmarked. This research has demonstrated that tall, heavy structures show little upper-structure vibratory response during hard-rock, urban blasting carried out in NYC. The Fire Department of New York City (FDNY) permits rock blasting and regulated limits for ground vibrations using the U.S. Bureau of Mines (USBM) safe blasting criteria. However, these regulations are often superseded by a 0.5 in/s (12.7 mm/s) limit imposed by the New York City Department of Buildings for historic and Landmarked buildings that are adjacent to the majority of blasting projects in the City. This onerous limit is often exceeded resulting in frequent stop work orders that increase the cost and time of rock excavation projects. The

Jan 1, 2019

By Lyle Dennis

Emphasis on increased production while maintaining rigid quality standards has necessitated a change in blasting technology at Dacotah Cement's limestone and gypsum quarries. The following three methods implemented during the past three years have yielded an increase in production through improved fragmentation.

Jan 1, 1996

By Brian W. Stump, David P. Anderson

Identification of seismic events detected under a Comprehensive Test Ban Treaty requires a clear physical understanding of the different types of seismic sources including mining explosions, rock bursts, mine collapse and small, shallow earthquakes. Constraint of the operative physical processes in the source region and linkage to the generation of seismic waveforms with particular emphasis on regional seismograms is needed. In order to properly address the multi-dimensional aspect of data sets designed to constrain these sources, we are investigating a number of modern visualization tools that have only recently become available with new, highspeed graphical computers that can utilize relatively large data sets. The results of this study will provide a basis for identifying important physical processes in the source region that contribute to regional seismograms.

Jan 1, 1995

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high speed photography to better understand the mechanisms of fracture and fragmentation.

Jan 1, 2015

By George W. MacDonald

ALFRED NOBEL was born at Stockholm on October 21st. 1833, and died on December 10th, 1896. Although Sobrero’s discovery of nitroglycerin dated back to 1847, this explosive was manufactured on a commercial scale for the first time in 1862, by Nobel at a factory which he erected at Heleneborg, near Stockholm. These works were entirely wrecked by an explosion in 1864. In 1865, he erected works, which are still in existence, at Winterviken, near Stockholm. In 1864 Nobel introduced modifications in the manufacture of nitroglycerin which were the subject of a patent (see footnote No. 1), and at the same time, claimed a process for the detonation of nitroglycerin. Nobel states that, up to that time, the method used for the manufacture of nitroglycerin consisted in pouring glycerin, drop by drop, into a mixture of sulphuric acid and nitric acid contained in a refrigerating mixture. In order that the nitroglycerin should not be decomposed, the temperature was not allowed to rise above 0° C.

Jan 1, 2012

By Ron Ketterling

We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes

Feb 1, 2020

By Roberto Golchi

This article describes the method used to quantify the Environmental Impact for the mining, by drilling and blasting, of a borrow pit for a gravity-dam. The affected environment was broken down into a number of components, such as public health and safety, social relationship, air and water quality, flora and fauna. The effect of the various impacting factors from the mining activities, both directly and indirectly, was then calculated for each environmental component. To do this, each impacting factor was first given a magnitude, a number based solely on the range of scenarios possible for the impacting factor. A matrix of weighting factors was then derived to systematically quantify, and normalise, the effects of each impacting factor on each environmental component. The overall impact upon each individual environmental component was then calculated by summing the weighted magnitudes for all the impacting factors.

Jan 1, 2003

By Ron Ketterling

Donna Summer wrote and recorded a song in 1983 with Michael Omartian called, “She Works Hard for the Money.” The song was inspired by her encounter with an exhausted rest room attendant, Onetta Johnson, who is mentioned in the song by name, and featured on the album’s back cover. ISEE President James Daley, in the May/June 2019 in The Journal of Explosives Engineering discussed the Six Pillars related to the ISEE. We will use the Internal Processes pillar to frame this discussion. The Internal Process Pillar includes five separate sub-committees – we will see how this concept applies to both ATF Explosives record-keeping compliance and business process compliance in general. We will discuss electronic and paper record keeping, what works and what doesn’t. We’ll review record keeping in light of those five sub-committees: Audit, Awards, Constitution, Ethics and Planning. You’ll come away with concrete steps you can use to improve your record keeping processes. This paper will show you how to make the hard work of inventory management and ATF record keeping work hard for you.